#include<iostream>
using namespace std;

class Sum
{
public:
	Sum()
	{
		_ret += _i;
		++_i;
	}

	static int GetRet()
	{
		return _ret;
	}

private:
	static int _i;
	static int _ret;
};

int Sum::_i = 1;
int Sum::_ret = 0;

class Solution
{
public:
	int Sum_Solution(int n)
	{
		Sum* arr = new Sum[n];
		return Sum::GetRet();
	}
};

int main()
{

	return 0;
}